Characterising the sleep-wake behaviour of adolescents in a sample of South African high school students in Makhanda, Eastern Cape
- Authors: Mandondo, Nathasha Luleka
- Date: 2021-10-29
- Subjects: Sleep-wake cycle South Africa Makhanda , Sleep deprivation South Africa Makhanda , Academic achievement South Africa Makhanda , Mood (Psychology) South Africa Makhanda , High school students Conduct of life , Teenagers Health and hygiene South Africa Makhanda , Teenagers Sleep South Africa Makhanda , Depression in adolescence South Africa Makhanda
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245714 , vital:51398
- Description: Sleep plays a significant role during adolescence. Overall, sleep is essential for growth and development, cognitive function, memory consolidation, concentration, alertness, mental and physical health, as well as the overall quality of life. During adolescence though, sleep-wake behaviour has been shown to undergo drastic changes, progressing from the early ages of 11-13 years through to late adolescence while attending school. During this period, adolescents experience later bedtimes, earlier waketimes, and less than recommended sleep durations, especially on weekdays during the school term. On weekends, however, adolescents tend to further delay their bed and wake times, resulting in discrepancies between week-and-weekend sleep-wake behavior. These changes are driven by a variety of systemic factors, that include biological, psychosocial, school, and behavioural changes that adolescents experience. The interaction of systematic factors has been described as the “Perfect Storm of insufficient and inappropriately-timed sleep” (Carskadon, 2011a; Crowley et al., 2018). While previous research on adolescent sleep has been focused mainly in countries of the Global North, there has been comparatively less research in the Global South, particularly in countries like South Africa, and in out of large city centres like Johannesburg and Cape Town. It is also not known what the impact of certain demographic factors, such as learner sex, boarding/day schooling, and public/private schooling is on sleep-wake habits. Therefore, the purpose of this study was to explore the sleep-wake behaviour of a sample of late adolescents from public and private schools in Makhanda in the Eastern Cape of South Africa and to make comparisons between different groups within. Method: This study is comprised of two phases. Phase one adopted a cross-sectional design to characterise Grade 12 learners' (final year students) sleep-wake behaviour across various public and private schools. This was achieved through the administration of an amended version of the School Sleep Habits Survey (SSHS). The SSHS included questions that capture demographic information, academic performance, sleep duration at different times of the week and also incorporated scales to assess daytime sleepiness, sleep-wake behavior problems, depressive mood, and chronotype. Phase two adopted an observational descriptive design. The sleep-wake behaviour of a sample of Grade 11 learners was tracked for 9 days using the Core Consensus Sleep Diary and Actigraphy. Data were not normally distributed and were thus analysed using non-parametric statistics and all data were displayed as the median and interquartile range (no 1-3). Results: Analysed surveys totalled 231. All participants were Grade 12s (final year of high school), aged between 17-19, from three private schools (n=152) and two public schools (n=79). The sample consisted of students identifying as females (n=94) and males (n=137). Participants self-identified as either Black/African (n=73), White (n=125), Colored (n=32) and as Indian (n=1). Over half of the sample lived in boarding houses/hostels (n=130) and slightly less than half (n=95) were day scholars. For Phase One, the median obtained for self-reported sleep duration on weekdays was 07hrs (06hrs-07hrs:18min) and 08hrs (07hrs-09hrs) on the weekend (p<0.01; z=10). The median for self-reported bedtime on weeknights was 11:00 (10:30-11:30) p.m., while on the weekends, it was an hour later i.e., 12:00 a.m. (11:00 p.m. -12:37 a.m.; p<0.01; z=9.4). Self-reported waketime on weekdays was 06:20 (06:00-06:30) a.m. and it was one-hour forty minutes later on weekends i.e., 08:00 (07:00-09:00) a.m. (p<0.01; z=13). With regards to sex differences on school mornings, females reported waking up 14 minutes later than their male counterparts (p<0.01; z=-3.1). On school mornings, day scholars reported significantly earlier waketimes than boarders (p<0.01; z=8.1). The opposite was found on weekends with day scholars reporting significantly later waketimes than boarders (p<0.01; z=-4.1) while day scholars reported going to bed significantly later than boarders during weekends (p<0.01; z=-2.7). There were noteworthy differences between types of schools with public school learners reporting earlier bed (p<0.01; z=3.9) and wake times (p<0.01; z=10) than private school learners on weekdays. On the weekend, however, public school learners reporting later bed (p=0.01; z=-2.7) and wake times (p<0.01; z=-4.4) than private school learners. Overall, the Grade 12 learners scored 12 (11-15) on the depressed mood scale indicating a trend towards high self-reported depressive symptoms, and 26 (23-30) on the ME scale, which demonstrated that this sample population reflects a preference for neither evenings nor mornings. The majority (75 %; n=174) of the Grade12 learners perceived themselves as getting too little sleep, 59% (n=134) reported waking up at least once during the night and 92% (n=213) reported experiencing varying degrees of daytime sleepiness. There was a relationship between caffeine consumption and usage of electronic devices (EDs) before bedtime and some sleep parameters. Specifically, the frequency of consumption of coffee/tea and soda had a medium and positive correlation with sleep onset latency as well as to the scale of sleep-wake problems. Academic performance was also positively and significantly correlated with self-reported mean weekday waketime and negatively correlated with mean weekend sleep duration as well as Weekend Waketime Delay (WWD). For Phase Two, the median self-reported sleep duration for 14 female boarders recorded in sleep diaries i.e.,07:32 (07:22-07:55) and the total sleep time (TST) recorded by the actigraphy i.e., 07:06 (06:54-07:35) and was less than the recommended sleep duration of 8-10 hours for adolescents and not significantly different (p=0.18; z=1.3). However, median sleep duration on the weekend was significantly longer on both actigraphs (08:16; 07:22-08:40) and sleep diaries (08:24; 07:59-08:51) and not significantly different (p=0.3; z=1.1). Overall, bedtimes, waketimes, and sleep onset latency, for both weekdays and weekends, did not differ significantly between the sleep diary responses and actigraph recordings. Discussion: Adolescents in this cohort, like many around the world report weekday sleep durations that are shorter than the recommended 8-10 hours. This may probably partly be explained by later bedtimes influenced by academic obligations, bedtime autonomy, and screen time as well as early waketimes influenced by school start times as indicated in the reasons given for bedtimes. Insufficient sleep during school nights, in this cohort, likely resulted in an accumulated sleep debt which may explain the extended sleep duration and later waketimes on weekends. Weekday waketimes were probably determined by commuting and school-related demands, specifically, school start times as indicated in the reasons given for waketimes. Thus, the results of this study do, in part, align with the factors outlined in the Perfect Storm model of poorly timed and insufficient sleep in adolescents proposed by Carskadon (2011a). Personal characteristics or contextual factors, such as being a boarder or a day scholar, attending a public or private school as well sex differences, accompanied by lifestyle factors such as the consumption of caffeine and usage of electrical devices may have interacted and influenced bed and wake times, resulting in what has been termed “a Perfect Storm of insufficient and inappropriately-timed sleep” in this cohort. Conclusion: The current study provided new insight into the sleep-wake behaviour of late adolescents in Makhanda, Eastern Cape of South Africa. More research is encouraged in the South African context. This knowledge can be used to implement contextually appropriate sleep hygiene education programs in the school curriculum and on an individual level. Furthermore, the results point to the fact that early school start times, in concert with other lifestyle and personal factors may be contributing to insufficient sleep in this group. These results, therefore, highlight the need for schools in this context to consider interventions such as delaying school start times to possibly improve sleep in this context. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
- Authors: Mandondo, Nathasha Luleka
- Date: 2021-10-29
- Subjects: Sleep-wake cycle South Africa Makhanda , Sleep deprivation South Africa Makhanda , Academic achievement South Africa Makhanda , Mood (Psychology) South Africa Makhanda , High school students Conduct of life , Teenagers Health and hygiene South Africa Makhanda , Teenagers Sleep South Africa Makhanda , Depression in adolescence South Africa Makhanda
- Language: English
- Type: Master's thesis , text
- Identifier: http://hdl.handle.net/10962/245714 , vital:51398
- Description: Sleep plays a significant role during adolescence. Overall, sleep is essential for growth and development, cognitive function, memory consolidation, concentration, alertness, mental and physical health, as well as the overall quality of life. During adolescence though, sleep-wake behaviour has been shown to undergo drastic changes, progressing from the early ages of 11-13 years through to late adolescence while attending school. During this period, adolescents experience later bedtimes, earlier waketimes, and less than recommended sleep durations, especially on weekdays during the school term. On weekends, however, adolescents tend to further delay their bed and wake times, resulting in discrepancies between week-and-weekend sleep-wake behavior. These changes are driven by a variety of systemic factors, that include biological, psychosocial, school, and behavioural changes that adolescents experience. The interaction of systematic factors has been described as the “Perfect Storm of insufficient and inappropriately-timed sleep” (Carskadon, 2011a; Crowley et al., 2018). While previous research on adolescent sleep has been focused mainly in countries of the Global North, there has been comparatively less research in the Global South, particularly in countries like South Africa, and in out of large city centres like Johannesburg and Cape Town. It is also not known what the impact of certain demographic factors, such as learner sex, boarding/day schooling, and public/private schooling is on sleep-wake habits. Therefore, the purpose of this study was to explore the sleep-wake behaviour of a sample of late adolescents from public and private schools in Makhanda in the Eastern Cape of South Africa and to make comparisons between different groups within. Method: This study is comprised of two phases. Phase one adopted a cross-sectional design to characterise Grade 12 learners' (final year students) sleep-wake behaviour across various public and private schools. This was achieved through the administration of an amended version of the School Sleep Habits Survey (SSHS). The SSHS included questions that capture demographic information, academic performance, sleep duration at different times of the week and also incorporated scales to assess daytime sleepiness, sleep-wake behavior problems, depressive mood, and chronotype. Phase two adopted an observational descriptive design. The sleep-wake behaviour of a sample of Grade 11 learners was tracked for 9 days using the Core Consensus Sleep Diary and Actigraphy. Data were not normally distributed and were thus analysed using non-parametric statistics and all data were displayed as the median and interquartile range (no 1-3). Results: Analysed surveys totalled 231. All participants were Grade 12s (final year of high school), aged between 17-19, from three private schools (n=152) and two public schools (n=79). The sample consisted of students identifying as females (n=94) and males (n=137). Participants self-identified as either Black/African (n=73), White (n=125), Colored (n=32) and as Indian (n=1). Over half of the sample lived in boarding houses/hostels (n=130) and slightly less than half (n=95) were day scholars. For Phase One, the median obtained for self-reported sleep duration on weekdays was 07hrs (06hrs-07hrs:18min) and 08hrs (07hrs-09hrs) on the weekend (p<0.01; z=10). The median for self-reported bedtime on weeknights was 11:00 (10:30-11:30) p.m., while on the weekends, it was an hour later i.e., 12:00 a.m. (11:00 p.m. -12:37 a.m.; p<0.01; z=9.4). Self-reported waketime on weekdays was 06:20 (06:00-06:30) a.m. and it was one-hour forty minutes later on weekends i.e., 08:00 (07:00-09:00) a.m. (p<0.01; z=13). With regards to sex differences on school mornings, females reported waking up 14 minutes later than their male counterparts (p<0.01; z=-3.1). On school mornings, day scholars reported significantly earlier waketimes than boarders (p<0.01; z=8.1). The opposite was found on weekends with day scholars reporting significantly later waketimes than boarders (p<0.01; z=-4.1) while day scholars reported going to bed significantly later than boarders during weekends (p<0.01; z=-2.7). There were noteworthy differences between types of schools with public school learners reporting earlier bed (p<0.01; z=3.9) and wake times (p<0.01; z=10) than private school learners on weekdays. On the weekend, however, public school learners reporting later bed (p=0.01; z=-2.7) and wake times (p<0.01; z=-4.4) than private school learners. Overall, the Grade 12 learners scored 12 (11-15) on the depressed mood scale indicating a trend towards high self-reported depressive symptoms, and 26 (23-30) on the ME scale, which demonstrated that this sample population reflects a preference for neither evenings nor mornings. The majority (75 %; n=174) of the Grade12 learners perceived themselves as getting too little sleep, 59% (n=134) reported waking up at least once during the night and 92% (n=213) reported experiencing varying degrees of daytime sleepiness. There was a relationship between caffeine consumption and usage of electronic devices (EDs) before bedtime and some sleep parameters. Specifically, the frequency of consumption of coffee/tea and soda had a medium and positive correlation with sleep onset latency as well as to the scale of sleep-wake problems. Academic performance was also positively and significantly correlated with self-reported mean weekday waketime and negatively correlated with mean weekend sleep duration as well as Weekend Waketime Delay (WWD). For Phase Two, the median self-reported sleep duration for 14 female boarders recorded in sleep diaries i.e.,07:32 (07:22-07:55) and the total sleep time (TST) recorded by the actigraphy i.e., 07:06 (06:54-07:35) and was less than the recommended sleep duration of 8-10 hours for adolescents and not significantly different (p=0.18; z=1.3). However, median sleep duration on the weekend was significantly longer on both actigraphs (08:16; 07:22-08:40) and sleep diaries (08:24; 07:59-08:51) and not significantly different (p=0.3; z=1.1). Overall, bedtimes, waketimes, and sleep onset latency, for both weekdays and weekends, did not differ significantly between the sleep diary responses and actigraph recordings. Discussion: Adolescents in this cohort, like many around the world report weekday sleep durations that are shorter than the recommended 8-10 hours. This may probably partly be explained by later bedtimes influenced by academic obligations, bedtime autonomy, and screen time as well as early waketimes influenced by school start times as indicated in the reasons given for bedtimes. Insufficient sleep during school nights, in this cohort, likely resulted in an accumulated sleep debt which may explain the extended sleep duration and later waketimes on weekends. Weekday waketimes were probably determined by commuting and school-related demands, specifically, school start times as indicated in the reasons given for waketimes. Thus, the results of this study do, in part, align with the factors outlined in the Perfect Storm model of poorly timed and insufficient sleep in adolescents proposed by Carskadon (2011a). Personal characteristics or contextual factors, such as being a boarder or a day scholar, attending a public or private school as well sex differences, accompanied by lifestyle factors such as the consumption of caffeine and usage of electrical devices may have interacted and influenced bed and wake times, resulting in what has been termed “a Perfect Storm of insufficient and inappropriately-timed sleep” in this cohort. Conclusion: The current study provided new insight into the sleep-wake behaviour of late adolescents in Makhanda, Eastern Cape of South Africa. More research is encouraged in the South African context. This knowledge can be used to implement contextually appropriate sleep hygiene education programs in the school curriculum and on an individual level. Furthermore, the results point to the fact that early school start times, in concert with other lifestyle and personal factors may be contributing to insufficient sleep in this group. These results, therefore, highlight the need for schools in this context to consider interventions such as delaying school start times to possibly improve sleep in this context. , Thesis (MSc) -- Faculty of Science, Human Kinetics and Ergonomics, 2021
- Full Text:
A comparison between the responsiveness of selected physiological and subjective mental workload indicators during real-world driving scenarios
- Authors: Schmidtke, Nadia-Jasmine
- Date: 2020
- Subjects: Automobile driving -- Physiological aspects , Automobile driving -- Psychological aspects , Automobile drivers -- Health and hygiene , Mental fatigue , Mental work -- Case studies
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/148115 , vital:38711
- Description: Sub-optimal levels of mental workload in automobile drivers is a risk factor for road accidents. However, mental workload as a construct cannot be directly measured. Common indicators of mental workload include heart rate frequency and variability, eye motion and subjective rating tools. Namely, the National Aeronautics and Space Administration Task Load Index (NASA-TLX), its modified, unweighted version called the Raw-TLX, and the Rating Scale of Mental Effort (RSME). Comparisons between the suitability and responsiveness of these mental workload indicators have been almost exclusively examined in driving simulators. However, real-world driving research is important as even high-fidelity simulators cannot capture the complexity of driving scenarios. Hence, this research aimed to compare the suitability and responsiveness of these mental workload indicators in response to real-world driving scenarios. Six participants drove along a set route for an hour while wearing a heart rate monitor and eye tracker. A dashcam was used to capture footage of the different driving scenarios encountered. The set route comprised of driving through the industrial, residential, provincial main road and Rhodes University campus areas. RSME scores were taken during brief stops after driving though each zone. The NASA-TLX questionnaire was administered on completion of the drive and analysed later as the modified Raw-TLX version. The data collected in response to the encountered driving scenarios were sorted into three meta-groupings. (1) Data was segmented according to the different areas that participants drove through. This was termed Area Events and were long duration scenarios of between five and thirty minutes. These driving scenarios were further segmented into two meta-groups with short duration driving scenarios (< 90 seconds). (2) The Common Events meta-group consisted of driving scenarios that were encountered by all participants. These were scenarios were anticipated by drivers. (3) The All Events meta-group was grouped according to all the driving scenarios that were encountered by participants. It consisted of both anticipated and unanticipated driving scenarios of short durations. Data were further analysed using a method of systematically selecting a threshold value for each mental workload indicator. Responses to driving scenarios which surpassed the threshold were considered indicative of an increase in mental workload. The total frequency of higher mental workload events was used as a determiner responsiveness (or ‘sensitivity’) for each mental workload indicator. Mental workload indicators were evaluated for their responsiveness and suitability for assessing mental workload. Results found blink frequency to be a responsive mental workload indicator for all categories of driving scenarios. Blink frequency and duration were the most responsive short duration mental workload indicators. Furthermore, the indicators were able to distinguish between higher and lower mental workload driving scenarios. However, blink parameters are also sensitive to driver fatigue and drowsiness. Further research on distinguishing mental workload from that of fatigue in response to real-world driving was recommended. Pupil diameter, fixation duration, saccade saccade duration and saccade amplitude were found to be responsive short duration mental workload indicators. However, these measures were not determined to be suitable for real-world driving applications. Pupil diameter was confounded by changing illumination levels. Fixation and saccade responses were confounded by the driving task itself as gaze could not be accounted for. For long duration driving scenarios heart rate frequency, heart rate variability: high-frequency power, blink frequency and RSME were found to be responsive and suitable MWL indicators. The Raw-TLX results could not be assessed for responsiveness as it was administered once. However, it was confirmed as a suitable cumulative mental workload indicator in the application of real-world driving. The moderate levels of workload reported by participants agreed with the experimental protocol that prevented inducing sub-optimal mental workload. Blink frequency shows promise as a responsive and suitable mental workload indicator for different types of driving scenarios. More research is needed regarding the assessment of mental workload during short durations using blink frequency and blink duration. For driving durations between five and thirty minutes long, further research into heart rate frequency, heart rate variability: high frequency power, and the RSME was recommended.
- Full Text:
- Authors: Schmidtke, Nadia-Jasmine
- Date: 2020
- Subjects: Automobile driving -- Physiological aspects , Automobile driving -- Psychological aspects , Automobile drivers -- Health and hygiene , Mental fatigue , Mental work -- Case studies
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/148115 , vital:38711
- Description: Sub-optimal levels of mental workload in automobile drivers is a risk factor for road accidents. However, mental workload as a construct cannot be directly measured. Common indicators of mental workload include heart rate frequency and variability, eye motion and subjective rating tools. Namely, the National Aeronautics and Space Administration Task Load Index (NASA-TLX), its modified, unweighted version called the Raw-TLX, and the Rating Scale of Mental Effort (RSME). Comparisons between the suitability and responsiveness of these mental workload indicators have been almost exclusively examined in driving simulators. However, real-world driving research is important as even high-fidelity simulators cannot capture the complexity of driving scenarios. Hence, this research aimed to compare the suitability and responsiveness of these mental workload indicators in response to real-world driving scenarios. Six participants drove along a set route for an hour while wearing a heart rate monitor and eye tracker. A dashcam was used to capture footage of the different driving scenarios encountered. The set route comprised of driving through the industrial, residential, provincial main road and Rhodes University campus areas. RSME scores were taken during brief stops after driving though each zone. The NASA-TLX questionnaire was administered on completion of the drive and analysed later as the modified Raw-TLX version. The data collected in response to the encountered driving scenarios were sorted into three meta-groupings. (1) Data was segmented according to the different areas that participants drove through. This was termed Area Events and were long duration scenarios of between five and thirty minutes. These driving scenarios were further segmented into two meta-groups with short duration driving scenarios (< 90 seconds). (2) The Common Events meta-group consisted of driving scenarios that were encountered by all participants. These were scenarios were anticipated by drivers. (3) The All Events meta-group was grouped according to all the driving scenarios that were encountered by participants. It consisted of both anticipated and unanticipated driving scenarios of short durations. Data were further analysed using a method of systematically selecting a threshold value for each mental workload indicator. Responses to driving scenarios which surpassed the threshold were considered indicative of an increase in mental workload. The total frequency of higher mental workload events was used as a determiner responsiveness (or ‘sensitivity’) for each mental workload indicator. Mental workload indicators were evaluated for their responsiveness and suitability for assessing mental workload. Results found blink frequency to be a responsive mental workload indicator for all categories of driving scenarios. Blink frequency and duration were the most responsive short duration mental workload indicators. Furthermore, the indicators were able to distinguish between higher and lower mental workload driving scenarios. However, blink parameters are also sensitive to driver fatigue and drowsiness. Further research on distinguishing mental workload from that of fatigue in response to real-world driving was recommended. Pupil diameter, fixation duration, saccade saccade duration and saccade amplitude were found to be responsive short duration mental workload indicators. However, these measures were not determined to be suitable for real-world driving applications. Pupil diameter was confounded by changing illumination levels. Fixation and saccade responses were confounded by the driving task itself as gaze could not be accounted for. For long duration driving scenarios heart rate frequency, heart rate variability: high-frequency power, blink frequency and RSME were found to be responsive and suitable MWL indicators. The Raw-TLX results could not be assessed for responsiveness as it was administered once. However, it was confirmed as a suitable cumulative mental workload indicator in the application of real-world driving. The moderate levels of workload reported by participants agreed with the experimental protocol that prevented inducing sub-optimal mental workload. Blink frequency shows promise as a responsive and suitable mental workload indicator for different types of driving scenarios. More research is needed regarding the assessment of mental workload during short durations using blink frequency and blink duration. For driving durations between five and thirty minutes long, further research into heart rate frequency, heart rate variability: high frequency power, and the RSME was recommended.
- Full Text:
Effectiveness of different interventions to reduce occupational sitting among office administrators at Rhodes University
- Authors: Malesa, Thato
- Date: 2020
- Subjects: Standing position , Sedentary behavior , Work environment , Employee health promotion , Office furniture -- Design , Industrial hygiene , Employees -- Health risk assessment , Human engineering , Compliance
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166403 , vital:41360
- Description: Background: Sitting for prolonged periods is common in the working environment. Office workers are exposed to long periods of sitting time at work. Research has reported associations between prolonged sitting and negative health implications. As such studies have proposed different interventions aimed at reducing sitting times in the workplace. The aim of the current study was to evaluate the effectiveness of two different interventions, physical intervention (sit-stand worktables) and personal intervention (instruction to stretch) on compliance and reducing occupational sitting behaviour. The study also aimed to investigate the effectiveness of interventions in improving or impairing mood. Methods: The study took the form of a fieldbased study atRhodes University, Makhanda, South Africa. Fifteen full–time office workers in different divisions participated in the study. Participants were randomly allocated to either the physical or personal intervention group. In both intervention groups, partic ipants were prompted to stand for five minutes every hour during the workday to either work in a standing position or perform stretches. Over the course of the experiment, desk occupancy, sitting/standing time and mood effect were recorded in both intervention groups Both intervention groups were monitored for a period of three months (58 days). Results: The study found that the physical intervention group was an effective approach to reduce prolonged sitting in the workplace in comparison to the personal intervention group. Over the course of the experiment, there was sustain usage of interventions in both groups, however, in the physical intervention group desk usage decreased overtime. The findings of the study also show that some participants were more compliant with the study procedures than others. It was also found that mood improved upon introducing interventions in the workplace. However, with the outcomes of the results, the study acknowledges that several factors emerged which are likely to impact compliance, which future studies may investigate. Conclusion: Although sit-stand worktables are expensive, it seems like introducing them was successful in reducing sitting time and changing sitting behaviour in comparison to an intervention that instruct s individuals to stand up and stretch.
- Full Text:
- Authors: Malesa, Thato
- Date: 2020
- Subjects: Standing position , Sedentary behavior , Work environment , Employee health promotion , Office furniture -- Design , Industrial hygiene , Employees -- Health risk assessment , Human engineering , Compliance
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/166403 , vital:41360
- Description: Background: Sitting for prolonged periods is common in the working environment. Office workers are exposed to long periods of sitting time at work. Research has reported associations between prolonged sitting and negative health implications. As such studies have proposed different interventions aimed at reducing sitting times in the workplace. The aim of the current study was to evaluate the effectiveness of two different interventions, physical intervention (sit-stand worktables) and personal intervention (instruction to stretch) on compliance and reducing occupational sitting behaviour. The study also aimed to investigate the effectiveness of interventions in improving or impairing mood. Methods: The study took the form of a fieldbased study atRhodes University, Makhanda, South Africa. Fifteen full–time office workers in different divisions participated in the study. Participants were randomly allocated to either the physical or personal intervention group. In both intervention groups, partic ipants were prompted to stand for five minutes every hour during the workday to either work in a standing position or perform stretches. Over the course of the experiment, desk occupancy, sitting/standing time and mood effect were recorded in both intervention groups Both intervention groups were monitored for a period of three months (58 days). Results: The study found that the physical intervention group was an effective approach to reduce prolonged sitting in the workplace in comparison to the personal intervention group. Over the course of the experiment, there was sustain usage of interventions in both groups, however, in the physical intervention group desk usage decreased overtime. The findings of the study also show that some participants were more compliant with the study procedures than others. It was also found that mood improved upon introducing interventions in the workplace. However, with the outcomes of the results, the study acknowledges that several factors emerged which are likely to impact compliance, which future studies may investigate. Conclusion: Although sit-stand worktables are expensive, it seems like introducing them was successful in reducing sitting time and changing sitting behaviour in comparison to an intervention that instruct s individuals to stand up and stretch.
- Full Text:
System analysis of fatigue in pilots and co-pilots executing short-hall flight operations
- Authors: Bennett, Cleo Taylor
- Date: 2020
- Subjects: Air pilots -- Health and hygiene , Fatigue , Work environment -- Psychological aspects , Work environment -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146622 , vital:38543
- Description: Background: This study was conducted as part of Denel’s South African Regional Aircraft (SARA) development project. Regional aircraft have a maximum flight time of 60 minutes. Hence, the study focuses on matters pertaining to the short-haul flight context. Pilot fatigue has been recognised as a safety concern in the aviation industry. It impacts on pilot performance across the board, not least in the short-haul context. However, the specific factors that lead to pilot fatigue in short-haul operations have not been well researched. Research Aim: To identify and examine the factors which influence pilot/co-pilot fatigue in short-haul aviation contexts. Method: Fatigue is multifaceted, and has multiple definitions and descriptions. It is acknowledged as a complex phenomenon, the development of which is dynamically influenced by various factors. Thus, a systems approach based on the work system model by Smith and Carayon-Sainfort (1989) was adopted for this study. A systems analysis was conducted in two parts: 1) a literature analysis, and 2) expert interviews. Results: Both the literature analysis and the interviews indicated that pilot fatigue in short-haul flight operations represent composite system outcomes influenced by various factors. The factors identified were structured (systematised) into categories, namely organizational factors, task-related factors, environmental factors, factors linked to technology and tools, and non-work-related factors specific to the individual pilot. An example of a task-related factor would be the performance by pilots of multiple take-offs and landings; organizational factors include work time arrangements and duty scheduling (e.g. unpredictable schedule, early starts/late finishes, number of flight sectors in a shift, extended working hours, numerous consecutive work days, standby duties, flight, duty and rest limitations (regulations and guidelines); and short turnaround periods); environmental factors might include the small pressurised cockpit environment, movement restriction, very low humidity, low air pressure, vibrations, high noise levels, low light intensity light, and inclement weather); there are many examples of how tools and technology utilized by pilots might affect their fatigue levels; and finally, pilot-specific non-work-related factors would include things like the pilot’s age, health (lifestyle), family stress, work experience and sleep environment. All of these factors were identified during the literature analysis and have a significant bearing on how fatigue could present in short-haul pilots/co-pilots. Other important fatigue-related factors revealed during the expert interviews included, organizational culture, time management, health implications of fatigue, and management of fatigue. Conclusions: Pilot fatigue is a complex and multi-factorial physiological condition. There are many interacting components which contribute to pilot fatigue in short-haul operations. These should be viewed from an integrated perspective and holistic, systems-based approaches should be taken to manage these issues, particularly in the context of short-haul operations. This would optimize pilot performance and well-being and, most importantly, improve the safety of the work environment to enhance overall operation safety. Limitations: The study does not quantify the contributions made to pilot fatigue by the various factors explored. Therefore, care needs to be taken when designing and implementing interventions based on this research.
- Full Text:
- Authors: Bennett, Cleo Taylor
- Date: 2020
- Subjects: Air pilots -- Health and hygiene , Fatigue , Work environment -- Psychological aspects , Work environment -- Physiological aspects
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/146622 , vital:38543
- Description: Background: This study was conducted as part of Denel’s South African Regional Aircraft (SARA) development project. Regional aircraft have a maximum flight time of 60 minutes. Hence, the study focuses on matters pertaining to the short-haul flight context. Pilot fatigue has been recognised as a safety concern in the aviation industry. It impacts on pilot performance across the board, not least in the short-haul context. However, the specific factors that lead to pilot fatigue in short-haul operations have not been well researched. Research Aim: To identify and examine the factors which influence pilot/co-pilot fatigue in short-haul aviation contexts. Method: Fatigue is multifaceted, and has multiple definitions and descriptions. It is acknowledged as a complex phenomenon, the development of which is dynamically influenced by various factors. Thus, a systems approach based on the work system model by Smith and Carayon-Sainfort (1989) was adopted for this study. A systems analysis was conducted in two parts: 1) a literature analysis, and 2) expert interviews. Results: Both the literature analysis and the interviews indicated that pilot fatigue in short-haul flight operations represent composite system outcomes influenced by various factors. The factors identified were structured (systematised) into categories, namely organizational factors, task-related factors, environmental factors, factors linked to technology and tools, and non-work-related factors specific to the individual pilot. An example of a task-related factor would be the performance by pilots of multiple take-offs and landings; organizational factors include work time arrangements and duty scheduling (e.g. unpredictable schedule, early starts/late finishes, number of flight sectors in a shift, extended working hours, numerous consecutive work days, standby duties, flight, duty and rest limitations (regulations and guidelines); and short turnaround periods); environmental factors might include the small pressurised cockpit environment, movement restriction, very low humidity, low air pressure, vibrations, high noise levels, low light intensity light, and inclement weather); there are many examples of how tools and technology utilized by pilots might affect their fatigue levels; and finally, pilot-specific non-work-related factors would include things like the pilot’s age, health (lifestyle), family stress, work experience and sleep environment. All of these factors were identified during the literature analysis and have a significant bearing on how fatigue could present in short-haul pilots/co-pilots. Other important fatigue-related factors revealed during the expert interviews included, organizational culture, time management, health implications of fatigue, and management of fatigue. Conclusions: Pilot fatigue is a complex and multi-factorial physiological condition. There are many interacting components which contribute to pilot fatigue in short-haul operations. These should be viewed from an integrated perspective and holistic, systems-based approaches should be taken to manage these issues, particularly in the context of short-haul operations. This would optimize pilot performance and well-being and, most importantly, improve the safety of the work environment to enhance overall operation safety. Limitations: The study does not quantify the contributions made to pilot fatigue by the various factors explored. Therefore, care needs to be taken when designing and implementing interventions based on this research.
- Full Text:
The workload of flight attendants during short-haul flight operations: a system analysis
- Authors: Bennett, Chloe Kayla
- Date: 2020
- Subjects: Flight attendants -- Health and hygiene , Employees -- South Africa -- Workload
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/123431 , vital:35437
- Description: Background and aim: Flight attendants forms a significant part in 24-hour aviation industry. Flight attendant fatigue is a significant problem in the aviation industry as it continues to jeopardize the ability to fulfil important safety and security roles which is critical in performance duty of a flight attendant. However, little attention has been accomplished to the workload, working conditions and fatigue of flight attendants crew in transport aircraft. In addition, there is currently less research that have also embraced the problematic of smaller regional/commercial operation (short-haul flight operations) inducing fatigue among short-haul flight attendants as the nature of this operation are often characterised with high productivity expectations in a demanding environment with high time pressures resulting in high workloads and fatigue. Thus, flight attendant fatigue and workload is a worldwide challenge in this operational environment and less attention has been given to the determining factors. Therefore, the aim of the study was to determine the workload factors contributing to flight attendant fatigue during short-haul flight operations. Methods (System analysis): To achieve the research aim, the work system analysis, based on the Smith and Carayon-Sainfort model was chosen as the main research approach which was conducted in two ways; based on existing literature and secondly based on expert interviews. This method provided a systemic aspect to understand the whole work system of flight attendants work during short-haul operations in order to identify all the contributing factors to flight attendant fatigue and workload. Results: The literature analysis and the data from the expert interviews highlighted significant findings to flight attendant fatigue and workload. The reasons for flight attendant fatigue operating short-haul flights can be found at organizational, task, individual, environmental levels and tools and technologies and due to the interaction of the factors. The main factors of flight attendants’ fatigue are thought primarily as a function of scheduling due to irregular, mixed schedules with early starts and late finishes, extended duty days (long working hours), as well as high workload, due to the short turnaround flights, the number of sectors flown in a single duty period and duty length and high jobs demands. In addition, flight duty and rest regulations, confined work space in the cabin, vibrations, noise and lighting, sleeping in an unfamiliar environment, family responsibilities all add to additional stress placed on the body which can influence workload and sleep and consequently influencing fatigue. Conclusion: Overall the study determined that flight attendant fatigue is a significant problem in modern industry of short-haul operations. Using this systematic approach (work system analysis based on the framework of the work system model developed by Smith and Carayon-Sainfort (1989) allowed for an accurate representation of the complexity of flight attendant work environment in short-haul aviation industries, thus contributed to an increased understanding of fatigue and risk factors that span the entire work system and aid in identifying the patterns in combination of work system variables that are associated with increased risk to flight attendant fatigue. Overall flight attendant fatigue is a product of interactions with the short-haul environment. It can have a negative impact on safety, performance and well-being. Therefore, it needs to be managed and dealt with in the near future.
- Full Text:
- Authors: Bennett, Chloe Kayla
- Date: 2020
- Subjects: Flight attendants -- Health and hygiene , Employees -- South Africa -- Workload
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/123431 , vital:35437
- Description: Background and aim: Flight attendants forms a significant part in 24-hour aviation industry. Flight attendant fatigue is a significant problem in the aviation industry as it continues to jeopardize the ability to fulfil important safety and security roles which is critical in performance duty of a flight attendant. However, little attention has been accomplished to the workload, working conditions and fatigue of flight attendants crew in transport aircraft. In addition, there is currently less research that have also embraced the problematic of smaller regional/commercial operation (short-haul flight operations) inducing fatigue among short-haul flight attendants as the nature of this operation are often characterised with high productivity expectations in a demanding environment with high time pressures resulting in high workloads and fatigue. Thus, flight attendant fatigue and workload is a worldwide challenge in this operational environment and less attention has been given to the determining factors. Therefore, the aim of the study was to determine the workload factors contributing to flight attendant fatigue during short-haul flight operations. Methods (System analysis): To achieve the research aim, the work system analysis, based on the Smith and Carayon-Sainfort model was chosen as the main research approach which was conducted in two ways; based on existing literature and secondly based on expert interviews. This method provided a systemic aspect to understand the whole work system of flight attendants work during short-haul operations in order to identify all the contributing factors to flight attendant fatigue and workload. Results: The literature analysis and the data from the expert interviews highlighted significant findings to flight attendant fatigue and workload. The reasons for flight attendant fatigue operating short-haul flights can be found at organizational, task, individual, environmental levels and tools and technologies and due to the interaction of the factors. The main factors of flight attendants’ fatigue are thought primarily as a function of scheduling due to irregular, mixed schedules with early starts and late finishes, extended duty days (long working hours), as well as high workload, due to the short turnaround flights, the number of sectors flown in a single duty period and duty length and high jobs demands. In addition, flight duty and rest regulations, confined work space in the cabin, vibrations, noise and lighting, sleeping in an unfamiliar environment, family responsibilities all add to additional stress placed on the body which can influence workload and sleep and consequently influencing fatigue. Conclusion: Overall the study determined that flight attendant fatigue is a significant problem in modern industry of short-haul operations. Using this systematic approach (work system analysis based on the framework of the work system model developed by Smith and Carayon-Sainfort (1989) allowed for an accurate representation of the complexity of flight attendant work environment in short-haul aviation industries, thus contributed to an increased understanding of fatigue and risk factors that span the entire work system and aid in identifying the patterns in combination of work system variables that are associated with increased risk to flight attendant fatigue. Overall flight attendant fatigue is a product of interactions with the short-haul environment. It can have a negative impact on safety, performance and well-being. Therefore, it needs to be managed and dealt with in the near future.
- Full Text:
The time course changes in selected fatigue indicators in moderately trained participants
- Authors: Maduna, Bongani Cyprian
- Date: 2019
- Subjects: Athletes -- Health and hygiene , Fatigue , Athletes -- Physiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76354 , vital:30553
- Description: Background: During daily physical activities, individuals will encounter some level of fatigue. This is especially true for athletes who exert their bodies to achieve superior performance and attempt to delay the onset of fatigue as far as possible. However, fatigue is a progressive process that is part of physical exercise. It is therefore, important to understand the various factors associated with fatigue. Objective: The purpose of this research project was to observe the changes in perceptual, physiological responses, and workload while participants performed a fatiguing cycling exercise task. In order to observe the aforementioned changes, one of the three variables, either perceptual, physiological responses or workload was kept constant, while the other two were observed as dependent variables. There were three test conditions, which permitted each variable to be kept constant in at least one of the three test conditions. Methods: Thirty-six apparently healthy university students were recruited for the study. The exercise was of 35 minute duration for each condition, with the data collection for HR (physiological response), RPE (perceptual response), and power output (workload) occurring at two minute intervals from the eighth minute until the thirtieth minute. The participants were required to perform a peak-power-output test in order set the relative performance ranges for each participant in order to elicit an observable fatigue response from all the participants. The three conditions included constant HR response, constant workload, and constant RPE response where each participant performed all of the above conditions on separate days.Results: The perceptual (RPE) response increased significantly (p<0.05) over time in all three test conditions, even under the constant RPE condition where it was expected to remain unchanged throughout the test duration. The HR response only demonstrated a significant (p<0.05) increase over time under the constant workload condition. Lastly, workload remained constant in all three testing conditions. Conclusion: Participants may be able to exercise for longer periods during sub-maximal exercise if they disregard the RPE warning response. In the current study, the RPE response illustrated that participants were being exerted more over time; however, the participants still had physiological and workload capacity to continue exercising. This research project has confirmed the fact that fatigue is a multifaceted phenomenon. Furthermore, it has been illustrated that RPE response alone as an indicator of fatigue onset may be misleading as participants did not breach the HR and workload steady state during the current research. Therefore, it may be more appropriate to assess fatigue onset through the assessment of more than one fatigue variable in order to ensure increased accuracy of the participants’ fatigue state assessment.
- Full Text:
- Authors: Maduna, Bongani Cyprian
- Date: 2019
- Subjects: Athletes -- Health and hygiene , Fatigue , Athletes -- Physiology
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/76354 , vital:30553
- Description: Background: During daily physical activities, individuals will encounter some level of fatigue. This is especially true for athletes who exert their bodies to achieve superior performance and attempt to delay the onset of fatigue as far as possible. However, fatigue is a progressive process that is part of physical exercise. It is therefore, important to understand the various factors associated with fatigue. Objective: The purpose of this research project was to observe the changes in perceptual, physiological responses, and workload while participants performed a fatiguing cycling exercise task. In order to observe the aforementioned changes, one of the three variables, either perceptual, physiological responses or workload was kept constant, while the other two were observed as dependent variables. There were three test conditions, which permitted each variable to be kept constant in at least one of the three test conditions. Methods: Thirty-six apparently healthy university students were recruited for the study. The exercise was of 35 minute duration for each condition, with the data collection for HR (physiological response), RPE (perceptual response), and power output (workload) occurring at two minute intervals from the eighth minute until the thirtieth minute. The participants were required to perform a peak-power-output test in order set the relative performance ranges for each participant in order to elicit an observable fatigue response from all the participants. The three conditions included constant HR response, constant workload, and constant RPE response where each participant performed all of the above conditions on separate days.Results: The perceptual (RPE) response increased significantly (p<0.05) over time in all three test conditions, even under the constant RPE condition where it was expected to remain unchanged throughout the test duration. The HR response only demonstrated a significant (p<0.05) increase over time under the constant workload condition. Lastly, workload remained constant in all three testing conditions. Conclusion: Participants may be able to exercise for longer periods during sub-maximal exercise if they disregard the RPE warning response. In the current study, the RPE response illustrated that participants were being exerted more over time; however, the participants still had physiological and workload capacity to continue exercising. This research project has confirmed the fact that fatigue is a multifaceted phenomenon. Furthermore, it has been illustrated that RPE response alone as an indicator of fatigue onset may be misleading as participants did not breach the HR and workload steady state during the current research. Therefore, it may be more appropriate to assess fatigue onset through the assessment of more than one fatigue variable in order to ensure increased accuracy of the participants’ fatigue state assessment.
- Full Text:
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